Curved Catheter and Methods for Making Same

ABSTRACT

A pre-curved catheter tube of a catheter assembly or other elongate medical device and methods for forming such a device using a heating procedure is disclosed. Pre-curving of the catheter tube is desirable to impart to the catheter assembly a desired positional configuration when the catheter assembly is inserted into a patient. The heating procedure may include heat sterilization procedures commonly used to sterilize medical devices prior to use. In one embodiment, therefore, a catheter assembly is disclosed, comprising an elongate catheter tube defining at least one lumen, and a tube constraint. The tube constraint is included with the catheter assembly and is configured to temporarily constrain the catheter tube in a curved configuration during a heating procedure of the catheter assembly so as to permanently form the catheter tube in the curved configuration after the heating procedure is complete and the catheter tube is released from the tube constraint.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 61/751,682, filed Jan. 11, 2013, and titled “Systems andMethods for Forming A Pre-Curved Catheter,” which is incorporated hereinby reference in its entirety.

BRIEF SUMMARY

Briefly summarized, embodiments of the present invention are directed toa pre-curved catheter tube of a catheter assembly or other elongatemedical device and methods for forming such a device using a heatingprocedure. Pre-curving of the catheter tube is desirable to impart tothe catheter assembly a desired positional configuration when thecatheter assembly is inserted into a patient. The heating procedure mayinclude heat sterilization procedures commonly used to sterilize medicaldevices prior to use.

In one embodiment, a catheter assembly is disclosed, comprising anelongate catheter tube defining at least one lumen, and a tubeconstraint. The tube constraint is included with the catheter assemblyand is configured to temporarily constrain the catheter tube in a curvedconfiguration during a heating procedure of the catheter assembly so asto permanently form the catheter tube in the curved configuration afterthe heating procedure is complete and the catheter tube is released fromthe tube constraint.

Examples of catheter assemblies that can benefit from the presentdisclosure include CVC, PICC, dialysis, peripheral IV and othercatheters, though the principles to be described herein can be appliedto catheters and elongate medical devices of a variety ofconfigurations.

These and other features of embodiments of the present invention willbecome more fully apparent from the following description and appendedclaims, or may be learned by the practice of embodiments of theinvention as set forth hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

A more particular description of the present disclosure will be renderedby reference to specific embodiments thereof that are illustrated in theappended drawings. It is appreciated that these drawings depict onlytypical embodiments of the invention and are therefore not to beconsidered limiting of its scope. Example embodiments of the inventionwill be described and explained with additional specificity and detailthrough the use of the accompanying drawings in which:

FIGS. 1A and 1B are various views of a catheter assembly including acurved catheter tube according to one embodiment;

FIG. 2 shows views of a bifurcation portion of the catheter assembly ofFIGS. 1A and 1B including a tube constraint according to one embodiment;

FIGS. 3A and 3B show the bifurcation portion of FIG. 2 in multipleconfigurations;

FIGS. 4A and 4B show various views of a bifurcation portion of acatheter assembly including a tube constraint according to oneembodiment;

FIGS. 5A and 5B show various views of a catheter assembly including atube constraint according to one embodiment;

FIGS. 6A-6D show suture wings including tube constraints according topossible embodiments;

FIG. 7 shows a cross sectional view of a bifurcation portion of acatheter assembly according to one embodiment;

FIG. 8 is a side view of a tube constraint for a catheter assemblyaccording to one embodiment;

FIG. 9 is a side view of a tube constraint for a catheter assemblyaccording to one embodiment; and

FIG. 10 is a side view of a tube constraint for a catheter assemblyaccording to one embodiment.

DETAILED DESCRIPTION OF SELECTED EMBODIMENTS

Reference will now be made to figures wherein like structures will beprovided with like reference designations. It is understood that thedrawings are diagrammatic and schematic representations of exemplaryembodiments of the present invention, and are neither limiting nornecessarily drawn to scale.

For clarity it is to be understood that the word “proximal” refers to adirection relatively closer to a clinician using the device to bedescribed herein, while the word “distal” refers to a directionrelatively further from the clinician. For example, the end of acatheter placed within the body of a patient is considered a distal endof the catheter, while the catheter end remaining outside the body is aproximal end of the catheter. Also, the words “including,” “has,” and“having,” as used herein, including the claims, shall have the samemeaning as the word “comprising.”

Embodiments of the present invention are generally directed to theformation of a pre-curved catheter tube or other elongate medical deviceusing the heat produced in heat sterilization procedures commonly usedto sterilize medical devices prior to use. Pre-curving of the cathetertube is desirable to impart to the catheter assembly a desiredpositional configuration when the catheter assembly is inserted into apatient. Examples of catheter assemblies include CVC, PICC, dialysis,peripheral IV and other catheters, though the principles to be describedherein can be applied to catheters and elongate medical devices of avariety of configurations.

Reference is first made to FIG. 1, which shows a catheter assembly(“catheter”) 10 configured in accordance with one embodiment. As shown,the catheter assembly (“catheter”) 10 includes an elongate catheter tube12 that defines one or more lumens longitudinally extending between aproximal end 12A and a distal end 12B of the tube. A bifurcation 14mates with the catheter tube 12 at the proximal end 12A thereof toprovide fluid communication between the catheter tube and one or moreextension legs 18.

A suture wing 16 is included with the bifurcation 14 for enablingsuturing of the catheter assembly 10 to the patient's skin or otherlocation. Though shown here as a discrete portion of the bifurcation,the suture wing in other embodiments can be integrally formed with thebifurcation.

FIGS. 1A and 1B show that the catheter tube 12 is compliant and isdisposed in a pre-curved configuration, wherein the tube crosses overitself or over another part of the catheter assembly. This is alsoreferred to herein as an “alphacurve” configuration. In addition to analphacurve or looped configuration, the catheter tube 12 can be bent orcurved in a variety of other configurations. Note also, that, thoughshown and described herein in connection with medical applications forproviding vascular access to a patient, the catheter assembly can beconfigured differently from what is shown and described herein for avariety of applications. For example, the principles to be taught hereincan be applied to a variety of catheter types and configurations,including CVCs, PICCs, PIVs, drainage, feeding, urinary catheters, etc.

As shown in FIG. 1B and additionally illustrated in FIG. 2, the catheterfurther includes in the present embodiment a tube constraint 20 sizedand configured to temporarily constrain the catheter tube 12 in a curvedconfiguration (also referred to herein as a pre-curved configuration),such as that shown in FIG. 1B. Temporary maintenance of the cathetertube 12 in such a curved configuration enables the curve to bepermanently set in the catheter tube—via subjecting the constrainedcatheter tube to a suitable heating procedure—even after the cathetertube is released from the tube constraint, thus desirably producing apre-curved catheter, similar to that shown in FIG. 1A, which can be usedfor various medical applications.

The tube constraint 20 of FIG. 1B is shown in FIG. 2 to include notches22 defined on both the bifurcation 14 and the suture wing 16. In detailand as shown, an elongate, laterally extending notch 22A is defined in abase 16A of the suture wing while a corresponding notch 22B is definedon a bottom surface 14A of the bifurcation. When the suture wing 16 isrotatably attached to the bifurcation 14 via receipt of a distal portionof the bifurcation through a loop 16B of the suture wing, the notches22A, 22B align such that a portion of the looped catheter tube 12 can beinterposed between the notches in a sandwiched configuration in such away as to securely hold yet not substantially compress the tube. Thispositional relationship maintains the catheter tube 12 in the loopedconfiguration shown in FIG. 1B until the tube is removed from thenotches 22A and 22B, as discussed below. As such, the notches 22A and22B are suitably sized to perform the above functionality. In oneembodiment, therefore, the notches can be sized according to thediameter size of the catheter tube, which size can vary as appreciatedby one skilled in the art. In another embodiment, the notches are sizedso as to provide more or less compression of the catheter tube, as maybe desired. Note further that the suture wing 16 further includes a pairof holes 16C for enabling the passage of sutures therethrough insecuring the catheter 10 to the patient's skin.

FIGS. 3A and 3B show that the notches 22A, 22B can be adjusted inposition along the bodies of the suture wing 16 and the bifurcation 14so as to provide different degrees of catheter tube bend. For instance,FIG. 3A shows the notches 22A and 22B disposed relatively more distallywith respect to the structure of the catheter 10 so as to provide arelatively smaller radius of curvature for the looped catheter tube 12when it is received within the notches. This in turn produces arelatively more tightly-looped curve in the catheter tube 12 afterformation. In contrast, FIG. 3B shows the notches 22A and 22B disposedrelatively more proximally with respect to the structure of the catheter10 so as to provide a relatively larger radius of curvature for thelooped catheter tube 12 when it is received within the notches. This inturn produces a relatively less tightly-looped curve in the cathetertube 12 after formation. Note that other locations on the catheterassembly 10 can be employed for fixing the catheter tube 12 in a loopedconfiguration.

The looped or curved configuration of the catheter tube 12 discussedabove is initially maintained by the tube constraint 20, e.g., thenotches 22A, 22B, such as is seen in FIG. 1B. The constrained cathetertube 12 is then subjected to a heating procedure of sufficient time,temperature, and duration as to permanently set the curved configurationof the tube so as to resemble that shown in FIG. 1A, as desired.

In the present embodiment, a heat sterilization procedure to sanitizethe catheter assembly before shipment to and use by customers occursafter catheter manufacture and further serves as the heating procedureto permanently set the curved configuration of the catheter tube 12(FIG. 1A). Though other types of heat-based sterilizing procedures maybe used, in the present embodiment an ethylene oxide (“ETO”)sterilization procedure is employed to sterilize the catheter 10. Theheat produced during the ETO sterilization procedure is sufficient inthe present embodiment to permanently set the catheter tube 12 in thecurved configuration shown in FIG. 1A even after the tube is releasedfrom the tubing constraint 20 after the ETO sterilization procedures iscomplete. As mentioned, other heat-based sterilization ornon-sterilizing heating procedures can be employed to impart to thecatheter tube the curved configuration. Examples include steamsterilization, autoclaving, etc.

In the present embodiment, the catheter tube 12 and bifurcation 14include an aliphatic polyether polyurethane sold under the nameTECOFLEX®, by Lubrizol Advanced Materials, Inc. of Cleveland, Ohio,though other thermoplastics can also be acceptably employed from whichthe catheter tube is manufactured so as to impart a permanent curve tothe catheter tube under heat sterilization or other suitable heatingprocedure. In one embodiment, a thermoplastic falling within a hardnessrange of between about 65 D and about 95 A can be used, thoughthermoplastics outside of this range can also be employed.

In light of the above and in connection with the presently discussedfigures, in one embodiment the curved configuration can be permanentlyset in the catheter tube 12 by first manufacturing the catheter assembly10 to include the components shown and described in connection with FIG.1A, or more or fewer components as may be appreciated by one skilled inthe art. The catheter tube 12 can then be placed in a curved (e.g.,looped) configuration by placing a portion thereof into the tubeconstraint 20, e.g., the notches 22A, 22B (FIGS. 1B, 2) in the presentembodiment, or other suitable tube constraint such that the curvedconfiguration is temporarily maintained. The catheter assembly is thenoptionally packaged in a package or suitable container, and subsequentlyplaced in a chamber where it is subjected to ETO or other suitable formof heat sterilization for a predetermined amount of time andtemperature. This process permanently sets the curved configuration inthe catheter tube 12. As mentioned, other suitable heating procedurescan be used in place of ETO or other heat-based sterilizationprocedures. Though the catheter tube 12 can then be removed from thenotches 22A, 22B that form the tube constraint 20 if desired, in anotherembodiment the catheter tube is left in the notches or other suitabletube constraint within the sealed and sterilized container until thecatheter assembly 10 is removed by the clinician in preparation forinsertion into the patient. Variations to this process are possible, asappreciated by one skilled in the art. Note that after the curve ispermanently set and the catheter tube is removed from the tubeconstraint, a limited amount of relaxation of the catheter tube curvemay occur. For instance, in one embodiment the catheter tube 12 as shownconstrained in FIG. 1B may, after having its curve permanently set andbeing released from the tube constraint, relax to the shape shown inFIG. 1A.

In various prophetic examples, permanent curving of polyurethane CVC andPICC catheter tubes (including a bifurcation including a suture wing oflow-density polyethylene (“LDPE”) or thermoplastic elastomer) via use ofa tube constraint during ETO heat sterilization procedures are believedachievable at the following temperatures and time combinations: about 55degrees Celsius (“C.”) for about 15 minutes; about 55 degrees C. forabout one hour; about 55 degrees C. for about 12 hours; about 100degrees C. for about 12 hrs; about 100 degrees C. for about one hour;about 100 degrees C. for about 15 minutes; about from about 220 to about255 degrees Fahrenheit (“F.”) for about 65 to about 80 seconds; and fromabout 230 to about 240 degrees F. for about 270 to about 330 seconds.Note that the above examples, like typical ETO sterilization procedures,are performed under vacuum, though it is believed that the presence of avacuum does not substantially affect the ability of the heatingprocedure to set the catheter tube in a permanent curved configuration.Generally, it is understood that permanent forming of the catheter tubein accordance with the present disclosure depends on several factors,including tube material, tube thickness, lumen geometry, etc. It isfurther appreciated that a wide variety of time and temperaturecombinations for the heating procedure are possible. Generally,relatively lower heating procedure temperatures will require relativelymore time with the catheter tube constrained in its curved configurationduring heating in order for the curve to be permanently set in the tube.Correspondingly, relatively higher heating procedure temperaturesrequire relatively less time of constraint to set the curve duringheating.

FIGS. 4A and 4B depict the tube constraint 20 according to anotherembodiment, wherein the tube constraint includes a notch 24 definedthrough the base 16A of the bifurcation suture wing 16. The notch 24 issized so that a portion of the catheter tube 12 is retained therebywithout constricting the tube portion. The notch 24 can be configured tohave a break or open portion in its perimeter such that the cathetertube 12 can be pushed through the open portion into the notch. Inanother embodiment, the notch perimeter is completely closed off suchthat the distal end 12B of the catheter tube 12 must be first passedthrough the notch for the notch to receive the tube. Note that in thepresent embodiment the suture wing 16 is configured to swivel about thebody of the bifurcation 14 such that the orientation of the curvedportion of the catheter tube 12 can be adjusted according to the desiredtube orientation once the curve is permanently set via the ETO heatsterilization or other suitable heating procedure.

FIG. 5 shows the tube constraint 20 according to yet another embodiment,wherein the tube constraint includes a form 28 that is shaped andconfigured to constrain a portion of the catheter tube 12 in a curvedconfiguration in preparation for permanent forming of the curve via ETOsterilization or other suitable heating procedure. As shown, the form 28includes a relatively flat, compliant body 28A including a suitablystrong material, such as paper, fiberboard, cardstock, cardboard, etc.In one embodiment, the form 28 includes a durable spun-bonded olefinsheet sold under the trademark TYVEK® by E. I. du Pont de Nemours andCo., though various other suitable materials can also be employed.

The form body 28A defines two hooked segments 30 that engage portions ofthe catheter assembly 10: one to wrap about a proximal portion of thecatheter tube 12; the other to wrap about one of the extension legs 18.The form body 28A further defines two holes 32 through which a portionof the curved catheter tube passes. The holes 32 are sized so as tosuitable restrain the catheter tube 12, thus enabling the form 28 totemporarily maintain the tube in a desired curved configuration. Oncethe catheter tube 12 has been subjected to a suitable heating procedureto permanently set the curve thereof, the form 28 can be removed fromthe catheter assembly 10 as desired. In one embodiment, instructions areprinted on the form 28 or otherwise provided to assist the user inremoving and/or disposing of the form. In one embodiment, the form 28can be configured such that it can be ripped/cut apart to remove it fromthe catheter assembly 10. For instance, form in one embodiment caninclude perforations to ease removal from the catheter assembly. Notethat the particular shape, size, and configuration of the form can varyfrom what is shown and described herein.

FIGS. 6A-6D depict details of the tube constraint 20 according to yetanother embodiment, wherein the tube constraint includes a clip 34disposed on a portion of the suture wing 16 and sized to temporarilyretain therein a portion of the catheter tube 12 in the curvedconfiguration. As illustrated, the clip 34 can be variously positionedon the suture wing 16 or other catheter-related component, such as themain body of the bifurcation and can be removable in one embodiment. Inparticular, FIG. 6A shows the clip 34 extending from the base 16A of thesuture wing 16 in such a way as to constrain the catheter tube 12 asshown in FIG. 6B. In contrast, FIGS. 6C and 6D show the clip extendingfrom a portion of the loop 16B of the suture wing 16. Note that variousother positional placements of the clip 34 are possible, both on thesuture wing or bifurcation, or elsewhere on the catheter assembly 10.

FIG. 7 depicts details of the tube constraint 20 according to yetanother embodiment, wherein the tube constraint includes a chamferedpocket 36 that can be included in the design of the base 16A of thesuture wing 16. The chamfered pocket 36 is configured so as tofacilitate ease of insertion into the pocket of a portion of thecatheter tube 12 without negatively affecting the retention force neededto retain the tube therein. The particular angle of the chamfer or otherconfiguration of the pocket 36 can vary from what is shown and describedherein.

FIGS. 8-10 depict details of the tube constraint 20 according to yetother embodiments. In particular, FIG. 8 shows the tube constraint 20 asincluding an attachment piece 40, which in turn includes a body 42 thatdefines a clip portion 44 that is configured to receive therein aportion of the catheter tube 12 in order to hold it in a curvedconfiguration. The attachment piece 40 further includes pegs 46 sizedand configured to be received within the holes 16C of the suture wing 16of the catheter assembly 10 (FIGS. 1A, 1B, 2) so as to temporarilysecure the attachment piece in place with the catheter assembly. Whenforming of the catheter tube 12 is complete, the attachment piece 40 canbe removed from the catheter assembly and discarded. The pegs 46 aresized to provide a removable interference fit with the suture wing holes16C, in one embodiment. In other embodiments, other solutions forsecuring the attachment piece to the catheter assembly can be provided.

FIG. 9 depicts details of the tube constraint 20 according to yetanother embodiment, wherein the tube constraint includes an attachmentpiece 50, which in turn includes a body 52 that defines a hole 54 thatis configured to receive therethrough a portion of the catheter tube 12in order to hold it in a curved configuration. The attachment piece 50further includes a peg 56 sized and configured to be received within oneof the holes 16C of the suture wing 16 of the catheter assembly 10(FIGS. 1A, 1B, 2) so as to temporarily secure the attachment piece inplace with the catheter assembly. When forming of the catheter tube 12is complete, the attachment piece 50 can be removed from the catheterassembly and discarded. The peg 56 is sized to provide a removableinterference fit with the suture wing holes 16C, in one embodiment. Inother embodiments, other solutions for securing the attachment piece tothe catheter assembly can be provided.

FIG. 10 depicts details of the tube constraint 20 according to yetanother embodiment, wherein the tube constraint includes an attachmentpiece 60, which in turn includes a body 62 that defines a loop portion64 that is configured to receive therethrough a portion of the cathetertube 12 in order to hold it in a curved configuration. The attachmentpiece 60 further includes a peg 66 sized and configured to be receivedwithin one of the holes 16C of the suture wing 16 of the catheterassembly 10 (FIGS. 1A, 1B, 2) so as to temporarily secure the attachmentpiece in place with the catheter assembly. When forming of the cathetertube 12 is complete, the attachment piece 60 can be removed from thecatheter assembly and discarded. The peg 66 is sized to provide aremovable interference fit with the suture wing holes 16C, in oneembodiment. In other embodiments, other solutions for securing theattachment piece to the catheter assembly can be provided. Note that, inthe embodiments of FIGS. 8-10, other solutions for attaching to thecatheter tube, apart from holes, clips, and loops, could be used andthat these components can be interchanged between the designs shown inFIGS. 8-10. In yet another embodiment, a dual-clip device can beemployed, wherein a first clip attaches to a first portion of thecatheter tube and a second clip attaches to a second portion of thecatheter tube to maintain the catheter tube in a curved, e.g., a looped,configuration.

In addition the above embodiments, other tubing constraintconfigurations for retaining the catheter tube in a pre-curvedconfiguration can be employed, including a portion of adhesive includinga glue dot or adhesive tape, a feature included with the catheterassembly container, a silicone insert, a removable clip, etc. In oneembodiment the tube constraint 20 prevents the catheter tube 12 fromcoming into contact with another portion of the tube or otherlike-material components, such as the body of the bifurcation 14, so asto avoid knitting of the two components together during heat-basedsterilization. Also, the tubing constraint is configured in oneembodiment to hold the catheter tube without damaging or deforming it.

Embodiments of the invention may be embodied in other specific formswithout departing from the spirit of the present disclosure. Thedescribed embodiments are to be considered in all respects only asillustrative, not restrictive. The scope of the embodiments is,therefore, indicated by the appended claims rather than by the foregoingdescription. All changes that come within the meaning and range ofequivalency of the claims are to be embraced within their scope.

What is claimed is:
 1. A catheter assembly, comprising: an elongatecatheter tube defining at least one lumen; and a tube constraintincluded with the catheter assembly that temporarily constrains thecatheter tube in a curved configuration during a heating procedure ofthe catheter assembly to permanently maintain the catheter tubesubstantially in the curved configuration after the heating procedure iscomplete and the catheter tube is released from the tube constraint. 2.The catheter assembly as defined in claim 1, wherein the heatingprocedure includes a heat sterilization procedure.
 3. The catheterassembly as defined in claim 2, wherein the heating procedure includesan ethylene oxide sterilization procedure.
 4. The catheter assembly asdefined in claim 3, wherein the ethylene oxide sterilization procedureis performed at a temperature of at least about 55 degrees Celsius. 5.The catheter assembly as defined in claim 5, wherein the ethylene oxidesterilization procedure is performed for a time of at least about 15minutes.
 6. The catheter assembly as defined in claim 1, wherein thecurved configuration includes a looped configuration of the cathetertube.
 7. The catheter assembly as defined in claim 1, wherein the tubeconstraint is permanently attached to the catheter assembly.
 8. Thecatheter assembly as defined in claim 1, wherein the tube constraint istemporarily attached to the catheter assembly.
 9. The catheter assemblyas defined in claim 1, wherein the tube constraint prevents a portion ofthe catheter tube retained by the tube constraint from physicallycontacting another portion of the catheter tube or bifurcation.
 10. Thecatheter assembly as defined in claim 1, wherein the tube constraintincludes at least one notch disposed on at least one of a bifurcationand a suture wing of the catheter assembly.
 11. The catheter assembly asdefined in claim 10, wherein the tube constraint includes a first notchdisposed on the suture wing and a second notch disposed on thebifurcation such that a portion of the catheter tube is interposedbetween the first and second notches in a sandwich configuration whenthe catheter tube is in the curved configuration.
 12. The catheterassembly as defined in claim 11, wherein the position of the first andsecond notches is predetermined so as to place the catheter tube in acurved configuration that defines a predetermined radius.
 13. Thecatheter assembly as defined in claim 1, wherein the tube constraintincludes a compliant form including at least one portion for attachingto the catheter assembly and at least one hole for receivingtherethrough a portion of the catheter tube for maintaining the cathetertube in the curved configuration.
 14. The catheter assembly as definedin claim 13, wherein the tube constraint includes a spun-bonded olefinsheet.
 15. The catheter assembly as defined in claim 1, wherein the tubeconstraint includes at least one clip disposed on at least one of abifurcation and a suture wing of the catheter assembly.
 16. The catheterassembly as defined in claim 1, wherein the tube constraint includes anadhesive material temporarily attached to a portion of the catheterassembly.
 17. A catheter assembly, comprising: an elongate catheter tubedefining at least one lumen; a bifurcation operably connecting theelongate catheter tube to at least one extension leg tube; and a tubeconstraint permanently included with the catheter assembly, the tubeconstraint temporarily constraining the catheter tube in a curvedconfiguration during a heating procedure of the catheter assembly, theheating procedure imparting a permanent curve to the catheter tube afterthe catheter tube is released from the tube constraint.
 18. The catheterassembly as defined in claim 17, wherein the catheter assembly furtherincludes a suture wing and wherein the tube constraint includes a firstnotch disposed on the suture wing and a second notch disposed on thebifurcation such that a portion of the catheter tube is interposedbetween the first and second notches in a sandwiched configuration whenthe catheter tube is in the curved configuration.
 19. The catheterassembly as defined in claim 18, wherein the permanent curve of thecatheter tube defines a loop.
 20. The catheter assembly as defined inclaim 18, wherein the suture wing is rotatably attached to thebifurcation and wherein the first notch is laterally defined across abase of the suture wing.
 21. The catheter assembly as defined in claim17, wherein the heating procedure includes an ethylene oxide heatsterilization procedure.
 22. The catheter assembly as defined in claim21, wherein the ethylene oxide sterilization procedure is performed in asubstantial vacuum at a temperature of at least about 55 degrees Celsiusfor a time of at least about 15 minutes.
 23. A method for permanentlycurving a catheter tube of a catheter assembly, the method comprising:constraining the catheter tube into a curved configuration; heating thecurved catheter tube for a predetermined time at a predeterminedtemperature; and releasing the catheter tube from the constrained curvedconfiguration after the heating is complete such that the catheter tubepermanently and substantially retains the curved configuration.
 24. Themethod for curving as defined in claim 23, wherein constraining thecatheter tube further includes temporarily affixing a portion of thecatheter tube to a tube constraint, the tube constraint at leasttemporarily included with the catheter assembly.
 25. The method forcurving as defined in claim 24, wherein constraining the catheter tubefurther includes inserting a portion of the catheter tube in at leastone notch provided on the catheter assembly.
 26. The method for curvingas defined in claim 23, wherein constraining the catheter tube furtherincludes constraining the catheter tube such that the catheter tubecrosses over itself in a looped configuration.
 27. The method forcurving as defined in claim 23, wherein heating the curved catheter tubefurther comprises heating the curved catheter tube via an ethylene oxideheat sterilization procedure.
 28. The method for curving as defined inclaim 27, wherein heating the curved catheter tube further includesheating the curved catheter tube via the ethylene oxide heatsterilization procedure in a substantial vacuum at a temperature of atleast about 55 degrees Celsius for a time of at least about 15 minutes.